Answer: you can break up any polygon into triangles. So then showing that triangles are congruent (with the same shape and size; equally). As 333 of the measurements, it can often show that two triangles are congruent.
Explanation: A triangle only has 333 sides and 333 angles. If we know 444 distinct side measures or 444 distinct angle measures, then we know the two triangles cannot be congruent. Count the size and measure them to see if they're equally same congruent shaped and size.
Example: congruent shapes are those that have the same shape and the same size. Two triangles are congruent if all of their sides are the same.
Extra Fact: SSS (side-side-side) All three corresponding sides are congruent. SAS (side-angle-side) Two sides and the angle between them are congruent. ASA (angle-side-angle)